#include <stdio.h>

#define ONE_FLAG (1<<0) // 0000 0000 0000...0000 0001
#define TWO_FLAG (1<<1) // 0000 0000 0000...0000 0010
#define THREE_FLAG (1<<2) // 0000 0000 0000...0000 0100
#define FOUR_FLAG (1<<3) // 0000 0000 0000...0000 1000

void print(int flags)
{
    if(flags & ONE_FLAG)
    {
        printf("one\n");
    }
    if(flags & TWO_FLAG)
    {
        printf("two\n");
    }
    if(flags & THREE_FLAG)
    {
        printf("three\n");
    }
    if(flags & FOUR_FLAG)
    {
        printf("four\n");
    }
}

int main()
{
    print(ONE_FLAG);
    printf("\n");
    print(ONE_FLAG | TWO_FLAG);
    printf("\n");
    print(ONE_FLAG | TWO_FLAG | THREE_FLAG);
    printf("\n");
    print(ONE_FLAG | TWO_FLAG | THREE_FLAG | FOUR_FLAG);
    printf("\n");
    return 0;
}
